From 882e9ccdc95a4efe6eaf35a640e06506e27594fd Mon Sep 17 00:00:00 2001
From: Justin Van Patten <jvp@justinvp.com>
Date: Tue, 13 Sep 2016 14:57:07 -0700
Subject: [PATCH] Update new String.Split methods to use optional params

The new `Split(string)` overload broke source compat with uses of
`Split(null)`, which is documented to split based on white space,
because it makes the call ambiguous between `Split(char[])` and
`Split(string)`.

To maintain source compatibilty, `Split(string)` has been removed,
leaving just the overloads with `StringSplitOptions` parameters, which
are now optional. Making `StringSplitOptions` optional allows calls
to `Split(string)` while maintaining source compat with calls to
`Split(null)` which still binds to `Split(char[])` in C#, VB, and F#.

The new `Split(char)` overloads get the same changes for consistency
with `Split(string)`.
---
 src/mscorlib/model.xml                        |  2 --
 .../src/System/String.Manipulation.cs         | 20 ++++---------------
 2 files changed, 4 insertions(+), 18 deletions(-)

diff --git a/src/mscorlib/model.xml b/src/mscorlib/model.xml
index 41ff879af30a..4a5991ee5d37 100644
--- a/src/mscorlib/model.xml
+++ b/src/mscorlib/model.xml
@@ -7123,14 +7123,12 @@
       <Member Name="Remove(System.Int32,System.Int32)" />
       <Member Name="Replace(System.Char,System.Char)" />
       <Member Name="Replace(System.String,System.String)" />
-      <Member Name="Split(System.Char)" />
       <Member Name="Split(System.Char,System.Int32,System.StringSplitOptions)" />
       <Member Name="Split(System.Char,System.StringSplitOptions)"/>
       <Member Name="Split(System.Char[])" />
       <Member Name="Split(System.Char[],System.Int32)" />
       <Member Name="Split(System.Char[],System.Int32,System.StringSplitOptions)" />
       <Member Name="Split(System.Char[],System.StringSplitOptions)"/>
-      <Member Name="Split(System.String)" />
       <Member Name="Split(System.String,System.Int32,System.StringSplitOptions)" />
       <Member Name="Split(System.String,System.StringSplitOptions)"/>
       <Member Name="Split(System.String[],System.Int32,System.StringSplitOptions)" />
diff --git a/src/mscorlib/src/System/String.Manipulation.cs b/src/mscorlib/src/System/String.Manipulation.cs
index e9568a6d03cd..8f456b6c6ffd 100644
--- a/src/mscorlib/src/System/String.Manipulation.cs
+++ b/src/mscorlib/src/System/String.Manipulation.cs
@@ -944,19 +944,13 @@ public String Replace(String oldValue, String newValue)
         }
 
         [ComVisible(false)]
-        public String[] Split(char separator) {
-            Contract.Ensures(Contract.Result<String[]>() != null);
-            return SplitInternal(separator, Int32.MaxValue, StringSplitOptions.None);
-        }
-
-        [ComVisible(false)]
-        public String[] Split(char separator, StringSplitOptions options) {
+        public String[] Split(char separator, StringSplitOptions options = StringSplitOptions.None) {
             Contract.Ensures(Contract.Result<String[]>() != null);
             return SplitInternal(separator, Int32.MaxValue, options);
         }
 
         [ComVisible(false)]
-        public String[] Split(char separator, int count, StringSplitOptions options) {
+        public String[] Split(char separator, int count, StringSplitOptions options = StringSplitOptions.None) {
             Contract.Ensures(Contract.Result<String[]>() != null);
             return SplitInternal(separator, count, options);
         }
@@ -1075,19 +1069,13 @@ private unsafe String[] SplitInternal(char* separators, int separatorsLength, in
         }
 
         [ComVisible(false)]
-        public String[] Split(String separator) {
-            Contract.Ensures(Contract.Result<String[]>() != null);
-            return SplitInternal(separator ?? String.Empty, null, Int32.MaxValue, StringSplitOptions.None);
-        }
-
-        [ComVisible(false)]
-        public String[] Split(String separator, StringSplitOptions options) {
+        public String[] Split(String separator, StringSplitOptions options = StringSplitOptions.None) {
             Contract.Ensures(Contract.Result<String[]>() != null);
             return SplitInternal(separator ?? String.Empty, null, Int32.MaxValue, options);
         }
 
         [ComVisible(false)]
-        public String[] Split(String separator, Int32 count, StringSplitOptions options) {
+        public String[] Split(String separator, Int32 count, StringSplitOptions options = StringSplitOptions.None) {
             Contract.Ensures(Contract.Result<String[]>() != null);
             return SplitInternal(separator ?? String.Empty, null, count, options);
         }